In recent years, a liquid crystal display having a larger screen and higher quality is prevailing and high quality is required with respect to a front contrast and a viewing angle property. Further, in accordance with popularization of cell phones and notebook personal computers, films of thinner thicknesses are desired.
A retardation film has been utilized to broaden the viewing angle of a liquid crystal display, for example, a cellulose derivative film is stretched to obtain retardation and then saponified to be laminated with a PVA polarizer film, whereby a polarizing plate provided with a function of retardation film is obtained.
However, since this cellulose derivative film is provided with retardation by stretching, the haze tends to be increased resulting in a problem of decrease in front contrast of a liquid crystal display.
Specifically in the case of a cellulose derivative film obtained by a solution casting method, since distribution of resin and plasticizer in the film is liable to be inhomogeneous when the film is stretched in the presence of a large amount of residual solvent, uneven force may be applied to the film when the film is stretched, which may cause a problem of too much haze.
In patent document 1, a method in which more retardation is obtained by use of a retardation increasing agent while decreasing haze as a total has been disclosed. However, although haze could be reduced in this method, it did not result in improvement of front contrast of a liquid crystal display. In Patent Document 2, a method to reduce haze has been disclosed, however, further higher front contrast is desired in these days, and, when a film is formed as disclosed in this patent document, adhesion of films may occur or, when the film is used in a liquid crystal display, color unevenness in reflected light from a liquid crystal display screen displaying black (hereafter also referred to as “reflection color unevenness”) tends to occur due to formation of streaks on the film.    Patent Document 1 Japanese Patent Application Publication Open to Public Inspection (hereafter referred to as JP-A) No. 2006-154803    Patent Document 2 JP-A No. 2003-170492